Lifting-jack



(N0 Model.)

J. 0. HAOKETT. LIFTING JACK.

No. 604,583. Patented May 24, 1898.

lJNiTnn STATES ATFNT @rrrcn JOHN C. I-IAOKETT, OF ST. LOUIS, MISSOURI.

LIFTING JACK.

SPECIFICATION forming part of Letters Patent No. 604,583, dated May 2 1,1898.

Application filed July 19, 1897. Serial No. 645,094. (No model.)

To all whom it may concern:

Be it known that I, JOHN C. IIAOKETT, of the city of St. Louis, State ofMissouri, have invented certain new and useful Improvements inLifting-Jacks, of Which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, forming apart thereof.

My invention relates to lifting-jacks; and it consists of the novelconstruction, combination, and arrangement of parts hereinafter shown,described, and claimed.

Figure 1 is a side elevation of my improved lifting-jack with thehand-lever elevated. Fig. 2 is a horizontal section taken approximately011 the line 2 2 of Fig. 1. Fig. 3 is a vertical section takenapproximately n the line 3 3 of Fig. 2 with the hand-lever depressed.Fig. 1 is a view in perspective of a lifting-plate. Fig. 5 is a view inperspective of the overbalanced pivoted fulcrum.

Referring to the drawings by numerals, 6 is the toothed post.

15 is the sliding block mounted upon the post 6 and carrying thelifting-plate 7.

8 is the hand-lever for operating the liftingplate.

9 is the overbalanced pivoted fulcrum which forms a connection betweenthe hand-lever and the toothed post, and 10 is the lockinglink whichholds the lifting-plate in its elevated position.

The toothed post 6 projects upwardly from the center of the horizontalbase-plate 11, and the post is T-shaped in cross-section,its first andsecond flanges forming the flat front face 12 and its third flangeprojecting backwardly from the junction of the first and second flanges,the rear edge of said third flange being notched to form theupwardly-projecting teeth 13. The projection 14 extends straight up fromthe upper end of the post in alinement with the face 12 at the time thecasting is made, but after the parts are put together said projection isbent forwardly to form a stop to limit the upward movement of thesliding block 15 and to hold the parts from being disconnected. Thesliding block 15 has a T-slot 16 formed from its rear face to receivethe toothed post 6. The lifting-plate 7 is rectangular in plan and isformed integral with the block 15.

The trunnions 17 and 18 are formed integral with the block 15 and extendfrom opposite sides of said block in alinement with each other. Abracket-shaped web 19 extends downwardly from the center of the plate 7,the rear edge of said web engaging the face 12 of the toothed post, asrequired, to form a brace to strengthen and support the plate 7. Thelifting-plate is placed in position with the toothed post 6 in theT-slot 16 and the plate in front of the post before the projection 14 isbent, thus forming a sliding connection between the plate and the post.

The hand-lever 8 consists of the bar 20 and the arms 21 and 22, formedintegral With the forward end of said bar. When the lever 8 is cast andbefore the parts are put together, the arms 21 and 22 are spread apartat their free ends, as required, to allow the block 15 and the trunnions17 and 18 to be inserted between the arms of said forward end, andbearings 23 and 24 are formed in the forward ends of said arms toreceive said trunnions 17 and 18. The arms 21 and 22 are slightly curvedupwardly as they extend forwardly from the bar 20, and bearings 25 and26 are formed horizontally through said arms a short distance back ofthe bearings 23 and 24.

The overbalanced pivoted fulcrum 9 consists of the curved plates 27 and28, mounted in parallel positions and connected by the fulcrum-bar 29and the weight 30. The trunnions 31 and 32 extend in horizontalalinement outwardly from the plates 27 and 28 and approximately at thecen ters of the plates. The lug 33 extends outwardly from near the lowerend of the plate 27. The overbalanced pivoted fulcrum 9, constructed asdescribed, is placed between the arms 21 and 22, and then said arms arebent toward each other until the trunnions 31 and 32 enter the bearings25 and 26 and the trunnions 17 and 18 enter the bearings 23 and 24:.

The locking-link 10 consists of the V-shaped bar 34:, having thebearings 35 and 36 formed upon its ends. When constructed, the V- shapedbar 34: is spread apart at its ends to allow of the links being placedin position above the arms 21 and 22 and with the bearings 35 and 36 atopposite ends of the trunnions 17 and 18. Then the ends of the bar arebent toward each other until said trunnions 17 and 18 enter saidbearings 35 and 36. After the parts have been put together as describedit is obvious that they cannot be taken apart without bending orbreaking some of the parts.

The forward end of the arm 21 will engage the lug 33 when the rear endof the bar 20 is elevated to nearly a vertical position. The weight 30overbalancing the fulcrum-bar 29 operates to hold the fulcrum-baryieldingly in engagement with the teeth 13. When it is desired to lift aload, the post is placed in position, with the plate 7 under the loadand with the plate 11 resting upon a suitable foundation. Then thehand-lever 8 is elevated bodily until the lifting-plate 7 is broughtinto engagement with the load. Then the free end of the bar 20 isdepressed, the overbalanced pivoted fulcrum engages one of the teeth13,and the lifting-plate 7 is elevated,thus lifting the load. When it isdesired to elevate the load but a short distance, one depression ofthe-hand-lever is sufficient. Then the link 10 is swung forwardly untilits central portion engages one of the teeth 13, as shown in dottedlines in Fig. 3, and the jack is locked to hold the load in its elevatedposition.

If it is desired to lift the load farther than can be accomplished byone depression of the hand-lever 8, then the locking-link is manuallyengaged and held yieldingly in engagement with the teeth 13, and bysucces-' sively operating the hand-lever the liftingplate will beelevated step by step, the load being held by the link 10, engaging oneof the teeth 13, while the fulcrum is being elevated to the next higherone of the teeth 13. When the hand-lever 8 is elevated to a verticalposition, the end of the arm 21 engages,

the lug 33 to swing the fulcrum-bar 29 out of engagement with the teeth13 and then the lifting-plate and hand-lever may readily be raised orlowered to any desired position upon the post.

I claim 1. In a lifting-jack, the toothed post 6 3 said post beingT-shaped in cross-section, its first and second flanges forming the flatfront face 12 and its third flange projecting backwardly from thejunction of said first and second flanges, the rear edge of said thirdflange being notched to form the upwardly-projecting teeth 13, thesliding block 15 having the T- slot 16 formed from its rear face, saidtoothed post 6 being mounted in said slot, the liftingplate 7 projectingforwardly from said sliding block, the trunnions 17 and 18 extendingfrom opposite sides of said block 15 in alinement with each other, thebracket-shaped web 19 extending downwardly from the center of said plate7 with its rear edge engaging the face 12 of the toothed post, ahand-lever having hearings to receive said trunnions and a fulcrumcarried by said hand-lever to engage said teeth, substantially asspecified.

2. In a lifting-jack, the toothed post 6; said toothed post beingT-shaped in cross-section, its first and second flanges forming the flatfront face 12 and its third flange projecting backwardly from thejunction of the first and second flanges and the rear edge of said thirdflange-being notched to form the upwardlyprojecting teeth 13, theprojection 14 formed integral with the toothed post 6 and designedto bebent forwardly after the parts of the jack have been assembled, theblock 15 having the T-slot 16 in its rear face, said toothed post beingmounted in said T-slot, said block being provided with the lifting-plate7, the trunnions 17 and 18 and the bracket-shaped web 19 forstrengthening the plate 7, a hand lever having hearings in which saidtrunnions operate,a fulcrum attached to said hand-lever and engagingsaid teeth, and a locking-link having hearings to receive said trunnionsand extending upwardly and backwardly in position to engage said teeth,substantially as specified.

3. In a lifting-jack, a T-shaped toothed post having upwardlyprojectingteeth formed upon the edge of its third flange, a sliding block having aT-slot to receive said toothed post as required to form a slidingconnection between the block and the post, a liftingplate projectingforwardly from said block,

trunnions projecting from opposite sides of said sliding block, thehand-lever 8 having hearings in which said trunnions operate; saidhand-lever consisting of the bar 20 and the arms 21 and 22 formedintegral with the forward end of said bar, said arms 21 and 22 havingbearings in their forward ends to receive said trunnions and the forwardends of said arms being spread apart to allow of the insertion of saidtrunnions and then bent toward each other to hold the trunnions inposition and the bearings 25 and 26 formed in said arms 21 and 22 ashort distance back of the bearings in which said trunnions operate; theoverbalanced pivoted fulcrum 9 mounted between said arms 21 and 22 andengaging the teeth of said post; said overbalanced pivoted fulcrumconsisting of the curved plates 27 and 28 in parallel positions andconnected by the fulcrum-bar 29 and the weight 30, the trunnions 31 and32 extending in a horizontal line outwardly from said plates 27 and 28and approximately at the centers of the plates and engaging in saidbearings 25 and 26, substantially as specified.

4. In a lifting-jack, a toothed post, said toothed post being T-shapedin cross-section and having upwardly-projecting teeth formed upon theedge of its third flange, a sliding block having a T-slot in its rearface in which said toothed post operates, a lifting-plate projectingforwardly from said block, trunnions projecting from said sliding block,a handlever having its forward end bifurcated and having hearings in theforward ends of the arms forming the bifurcated portion to re- IIO IOhand-lever and the lug 33 extending outwardly from nearthe lower end ofone of said curved plates and in position to be engaged by the end ofone of said arms of said handlever, substantially as specified.

In testimony whereof I affix my signature 15 in presence of twowitnesses.

JOHN G. HACKETT. Witnesses:

EDWARD E. LONGAN, ALBERT J. MOOAULEY.

